Apparatus for the treatment of textile strands



Sept. 28, 1948. JACKSON r 2,450,045

APPARATUS FOR THE TREATMENT oF TEx'rILE STRANDS Filed Jan. 15, 1943 IR/F IN VEN TORS T. JACKSON. F. B. HILL BY WYW ATTORNEYS Patented Sept. 28, 1948 APPARATUS FOR THE TREATMENT OF TEXTILE STRANDS Thomas Jackson and Frank Brentnali Hill. Spandon, near Derby, England aaaignors, by Inesne assignments, to Celanese Corporation of Amer-v ica, a corporation of Delaware Application January 15, ms, Serial No. 412.4

in Great mum July 11, ms

2 Clainu. (Cl. 26 59.5)

This invention is concerned with improvements in or relating to the treatment of textile and other materials and particularly with improvements in processes and apparatus for the treatment of yarns and other materials in a closed chamber with fluid media during their travel from one point to another.

The known apparatus for the treatment of yarns and other materials during their travel from one point to another with fluid treatment media comprise a substantially closed chamber, into which the materials pass through oriflces which have dimensions only slightly greater than those of the cross-sections of the material in order to reduce loss of treatment medium as far as possible. With such apparatus it is necessary, each time that a fresh batch of materials is to be treated, to dismantle the apparatus sufliciently'to make it possible to pass the materials through the orifices by hand. This involves loss of treatment medium, and also loss of heat-when the operation is one carried out at a high temperature, owing to the necessity for allowing the apparatus to cool before it can be handled. Moreover it takes up the time of the operatives and involves an extra overhead charge on account of loss of output while apparatus is standing idle.

The presentdnvention relates to an improved fluid treatment apparatus which is much simpler to thread-up than the known apparatus. The apparatus comprises a substantially closed chamber for treatment fluid provided with an injector which serves as inlet orifice for the materials.

The invention also includes processes in which.

into the treatment chamber and means for setting up an induced fluid current through this tube into the chamber. When the materials to be treated are presented to the end of the tube remote from the chamber this current sucks them through the tube into the treatment chamber. More than one injector may be provided in a chamber if required.

A very satisfactory form of injector comprises a central tube through which the materials pass and which is surrounded by a larger tube forming with the inner tube an annulus through which the fluid producing the induced fluid current'is forced. Either fluid may e. g., be steam, water, air or an inert gas.

The accompanying drawing shows diagrammatically one suitable form of apparatus for carrying out the present invention- Referring to the figure, yarns I are drawn by feed rolls I from packages I on a creel l and introduced into a substantially closed pressure chamber I provided with an inlet oriflce I and an outlet oriflce I for the yarns. The yarns are positively drawn through the treatment or pressure chamber I by means of positively driven feed rolls I and are taken up on bobbins or pack-.

ages I, the feed rolls I being driven at a higher rate of speed than the feed rolls 2. The chamber 5 is provided with a pressure gauge II, a relief valve II and a drain I! for withdrawing water from the chamber.

The inlet orifice I of the chamber is fltted with an inJector device ll. which comprises a central tube ll through which the yarns pass. the tube It being provided with a valve-controlled water inlet It, and an outer tube It surrounding the inner tube and forming therewith an annular passage l'i. Air or other fluid medium, such as steam, is introduced into this annular space through the valved inlet II to produce an injector action and draw air and the yarns through the central tube into the stretching or treatment chamber.

The present invention is of chief importance in connection with the stretching of artificial yarns having a basis of an organic derivative of cellulose. As is well-known, the tenacity of such artiflcial yarns can be increased by stretching them in the presence of a suitable softening agent, one of the most important methods of stretching such materials being based upon the use of saturated or wet steam under pressure as the softening agent. Such a process has been described in U. 8. Patent No. 2,142,722 which describes stretching operations carried out while the yarns pass through a substantially closed chamber containing saturated or wet steam and provided with inlet and outlet orifices for the yarns.

In stretching yarns of an organic derivative of cellulose in saturated or wet steam in a closed chamber, as is described in the above speciflcation, a current of steam issues from the yarn inlet orifices in a direction opposite to that of the travel of the yarns. This current exerts a tension on the softened yarns in the stretching chamber and ameter.

The preferred form of apparatus in accordance with the present invention provides a means of attaining the same result in a simpler manner and avoiding the necessity for an end-chamber.

The preferred form of apparatus comprises a substantially closed stretching chamber which is provided with a special form of injector which serves both as an inlet for the yarn and also for the introduction, continuously with stretchwall of the stretching chamber, comprises a cen-.

tral tube through which the yarn passes and which is provided with a valve-controlled water inlet, and an outer tube surrounding the inner tube'and forming with it an annular passage through which air or other fluid can be blown to produce an injector action and draw air from s I the atmosphere through the central tube into the stretching chamber. The injector may e. g. be 1 to 3 inches in length and A; to 1 inch in di- A stretching chamber may be provided with a number of injectors so that a number'of ends of yarn can be stretched, but it is preferred to have only one injector in a chamber.

In carrying out a stretching operation by means of an apparatus provided with a single injector the valve on the water inlet of the injector i closed and a current of air is blown through the annular passage so as to induce a current of air through the central tube. The yarn is taken from a source of supply, e. g., a

'bobbin, passed in non-slipping contact with a feed device and then presented to the end of the tube through whichit is drawn by the induced air current. It is then passed through an outlet in the opposite wall of the chamber and led first to a stretching device and thence to a take-up mechanism. If the path of the yarn through the stretching chamber i sufficiently short the current of air from the iniector may be willcient to carry the yarn through the outlet, particularly if the outlet end of the chamber is tapered in the form of a truncated cone. This operation may be assisted by the use of an outlet similar to the inlet but functioning as an ejector instead of an injector. However if this method of treading-up through the outlet is not practicable then this part of the operation may be done by hand. In this case the outlet may be drilled in a threaded disc, having a diameter of e. g., /2-1 inch, which screws into a socket in a wall of the chamber. When the disc is removed the injector air current carries the yarn through the comparatively large opening, when it can be hand-threaded through the orifice in the disc, after which the disc is screwed into the socket.

When threading-up of the apparatus has been completed the yarn is passed through the stretching chamber, steam is introduced through the annular passage of the injector and the valve on the water inlet i opened and water passed through the central tube in contact with the yarn. The yarn thus emerges from the injector carrying with it a film of water and comes immediately into contact with steam. It is thus brought very rapidly from-an unsoftened condition to asoftened condition in which it is suitable for stretching, and, moreover, any risk of its coming into contact with patches of dry steam is eliminated.

the specifications referred to above.

, 4 A voluminous yarn of high tenacity and uniform properties can thus be obtained.

Instead of introducing steam into the chamber through the injector separate steam jets may be employed but this involves a complication of the apparatus without as a rule obtaining any improvement in the products.

The stretching conditions employed in using the novel apparatus are similar to those employed in the stretching operations described in The pressure of the water entering the chamber is, however, higher, and preferably substantially higher than that of the steam used. The pressure difference may, for instance, be about 5 pounds per square inch but usually better results are obtained if water is employed, e. g., at a pressure of 10, or pounds per square inch higher than that of the steam. The temperature of the water is preferably low, for example from atmospheric temperature up to or C. The steam pressure employed will depend upon the steam temperature required and this again will depend primarily upon the degree of stretch and also to some extent on the particular type of yarn being stretched. For stretching yarns of acetone-soluble cellulose acetate to from 10 to 20 times their original length, which is usually the most desirable degree of stretch, steam temperatures of between 135 and 142C. are generally most suitable. Thus in such operations the steam pressure (gauge) will usually be between 30 and pounds per' square inch, and the water pressure between 35 and pounds per square inch.

Stretching and other treatments of yarns and other materials with fluid media may be carried out while the materials are travelling in a horizontal plane or at an angle to' the horizontal. Particular advantages, however, are obtained when the treatment is carried out with the injector and treatment chamber in a vertical position or substantially so, so that materials travel vertically or substantially so. Such an arrangement reduces the floor space occupied by the apparatus and also render the whole apparatus much more accessible to the operatives. When the operation in question is the stretching of yarns and other materials of an organic derivative of cellulose we have found that upward stretching should be eflected, much better results being obtained by this method than when the materials travel downwards during the operation. A further advantage of this method of stretching when wet steam is employed is that lower steam temperatures are required in order to obtain the optimum results.

The optimum sizes of the orifices through which yarn enters and leaves the injector and leaves the chamber can only ,be determined by experiment since they depend upon other factors, for example the denier of the yarn to be stretched and the degree of stretch. Usually, however, orifices having diameters of about 0.02", 0.03" or 0.04" are suitable for yarns having an initial denier of about 1000, larger orifices being required if yarns of substantially greater denier are treated. For example, with yarns or slivers having deniers of 10,000 to 20,000 the diameters of the yarn input and output orifices may vary from about 0.05" to 0.1" and of the injector orifice from about 0.09" to 0.14".

As a rough approximation it may be stated that it has been found that for different yarn deniers the orifice diameters giving the best resuit are proportional to the square roots of the deniers.

The length of the stretching or other treatment chamber will also depend upon the denier of the yarn and other factors. For example, with yarns having an initial denier of about 1,000 suitable lengths are about 6, 9 or 12" whereas with yarns or slivers having initial deniers of 10,000 or 20,000 it is usually desirable to increase the length, for example. to 20 or 30". The diameter of the stretching chamber may vary, for example, from 1 or 2" to 4" or more.

The apparatus described in the present application renders it possible to obtain yarns of high quality at high stretching speeds, for example at take-up speeds of 150 to 300 metres per minute or more.

In the form of apparatus specifically described above the iniector is positioned in a wall of a stretching chamber which may have a diameter several times as great as that of the injector.

The use of the apparatus according to the present invention has been described principally in relation to the stretching of yarns made of an Organic derivative of cellulose in saturated or wet steam, since it is for this purpose that the apparatus is of greatest importance. It will be appreciated. however, that its value is not confined to such an operation. It may be employed, for instance, in stretching yarns and other materials, for example ribbons, having a basis of other substances, particularly thermoplastic substances. e. g., polyamides or p lyvinyl compounds. The apparatus may also be employed for stretching operations in which the stretch-assisting agent is water or other liquid. Its use is further not confined to stretching operations but extends to all fluid treatments of materials carried out during their passage through a substantially closed treatment chamber. Moreover, while the injector type of orifice which forms the principal feature of the present invention is of chief importance when it is employed not only as an automatic means of threading-up but also as a means of introducing treatment fluid it can also be employed solely for threading up purposes. In such cases the water inlet into the central tube can be dispensedwith.

Having now described our invention what we desire to secure by Letters Patent is:

1. Apparatus for the treatment of yarns and similar materials during their passage from one point to another, which comprises a substantially closed treatment chamber. an injector positioned in a wall of said chamber having an inner member serving as an inlet orifice for the materials and adapted to be connected to a water supply, and an outer member adapted to produce an induced current of air through the inner member into the chamber and to be connected at will either to a compressed air supply or to a supply of wet steam, and an outlet orifice for the exit of the materials from the chamber.

2. Apparatus for the treatment of yarns and similar materials during their passage from one point to another, which comprises, in combination with a positively driven forwarding device adapted to feed the materials to the chamber and a positively driven forwarding device adapted to draw the materials from the chamber at' a rate faster than that at which they are fed to the chamber by the first mentioned forwarding device, a substantially closed treatment chamber, an injector positioned in a wall of said chamber having an inner member serving as an inlet orifice for the materials and adapted to be connected to a water supply, and an outer member adapted to produce an induced current of air through the inner member into the chamber and to be connected at will either to a compressed air supply or to a supply of wet steam, and an outlet orifice vfor the exit of the materials from the chamber.

THOMAS JACKSON. FRANK BREN'I'NALL HILL.

assurances crran The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 

